The invention relates to a combination of a plug, suitable for connection to a current-consuming device, for example a lamp, and a track receptacle having at least two mutually insulated current conductors. The plug is provided with at least two electrical contact pins for contacting the conductors in the receptacle and comprises a first part and a second part which is movable relative thereto. These parts are held in a first relative position by at least one spring. When the plug is coupled to the receptacle the force of the spring also provides the contact pressure between the contact pins and the current conductors. The receptacle encloses a space which is accessible via an opening extending in a longitudinal direction of the receptacle. The opening is bounded by two flanges. The plug includes electrically insulating supporting blocks arranged in such a manner that, when the plug is coupled to the voltage rail, these blocks are located between the facing edges of the two flanges and close fit each of two facing edges of the flanges in at least two different places.
Such a combination is disclosed, for example, in Netherlands Patent Application No. 7113699. An advantage of this known combination is that the moment of force which may be exerted by the current-consuming device connected to the plug is exerted only on the first part of the plug and the contact pressure between the contact pins and the current conductors obtained by spring action is not influenced by it. Furthermore, when the plug is coupled to the receptacle, the plug cannot be rotated about an axis perpendicular to the receptacle.
The disadvantage of the known combination is that upon coupling the plug to the receptacle, the contact pins can contact the current conductors before the current collector has reached its fixed final position with respect to the voltage rail.